Ejection molding apparatus



Sept. 29, 1953 H, P, HooPEs 2,653,370

EJECTION MOLDING APPARATUS Filed Nov. 25, 195o 2 sheets-sheet i l 1 f r i' 'I l' i I l i 1----- I HARRY R Hoo/Es ATTORNEY 2 Sheets-Sheet 2 HA 'PRY P. HOOPE'S ATTORNEY H. P. HOOPES Sept. 29, 1953 EJECTION MOLDING APPARATUS Filed Nov. 25, 1950 Patented Sept. 29, 1953 JEoTI'oN MoLDING APPARATUS Harry P. Hoopes, Berkeley, Calif., assigner 'to Pbcl) Pldllcts 111C., sal). FliSC, Calif.,

corporation of Delaware nnpiieatin November 25, 1950, serai No. 197,579

(o1. cs lz) 10 Claims.

This invention relates toefnoiding apparatus, and more particularlyto such apparatus adapted for the molding of light weight insulating matee rial from an aqueous slurry of the same,A such as magnesia insulation or insulation shaped from a slurry containing reactable calcareousesilicious materials, and more particularly to a special structure adjacent* the bottom end of the mold to permit drainage of slurry from the mold so as to obviate incrustation which would interfere with the movement of piston actuating rods passing through such structure. e

insulating materials of the type described which are particularly adapted for use with the molding apparatus of this invention are disclosed in a's'signees Patent No. 2,209,754, dated July 3o, 194D, for the production of magnes'ia insulation, :and Patents Nos. 2,432,98`1, dated December 23, i947, and 2,483,498, dated October 4, 1949, for the production of insulation made by the raction o'f calcareous and silicious r'rlaterials. In the methods of these patents, the 'slurry is poured into a mold cavity, and the mold is heated to set the slurry to a iirm Yself-supporting mass in a relatively short time, after which the set mass is ejected from the mold in self supporting form. In the case of magnesia insulation, the set mass is then dried, while in the case of the reactable calcareou's-silicious insulation, it is indurated and then dried. l e

In the manufacture of tubular pipe covering, the mold comprises a jacket formed of an `outer shelland an inner moldliner; heating fluid being circulated through the jacket space between the shell and the liner. drel is positioned Vwithin the liner and spaced therefrom to provide a cylindrical mold cavity between the liner and the core. Heating fluid is also circulated through the core; and a piston is providedwto eject the set material from the mold cavity. The piston is actuated by rods which extend through a closure member at the lower engl of the mold cavity; summarizing this invention, it comprises a special structure of the aforementioned closure member which is such as to prevent incrustation from aTecting free movement of the piston actu- 'ating rods through the member, thereby obviatlng damage to the mold, or relatively frecuent replacement of parts. This is accomplished by providing drainage passages in the closure member Athrough which the piston actuating rods extend, which are large enough in comparison to thehdianieter of the rods to provide ample clearance for drainage of slurry through such pas- A hollow mold core or man= CTI sages. incrustation forms rapidly when thejrnpid may be used alternately for molding magnesie in- Sul'ation and the calcareous-silicious insulation, because these two different materials when emiployed in the same mold enter into a chemical reaction resulting in hard incrustation. Objects of the invehtionwwill become apparent from a perusal of the following description thereof.

Referring to the drawing: l Y

Fig. 1 is a vertical sectional view through a portion of Aone embodiment of the molding a'pparatus of this invention in which the aforementioned drainage passages are provided in a special fluid distributing member; the View being broken away to shorten the same;`

Fig. 2 i's a view similar to Fig'.V 1 taken in a plane at a 45 angle to Fig. l as indicated by section line 2 2 in Fig". l; portions of the structure being omitted from the view and portions being shown broken away to illustrate more clearly the construction; e l t Fig, 3 is a horizontal section taken in a plane indicated by line 3 3 in Fig. l;

v Fig. l is arhorizohtal `'section taken in a plane indicated by line 4 4 in Fig. 1; Y t

Fig. 5 is an isometric View of the fluid distributing member employed at the lower end of the mold;

Fig. 6 is 'a bottoni sectional elevation taken in a plane indicated by line 6 6 in Fig. 1; t Y

Fig. 7 is a fragmentary vertical sectional view through the lower portion of another embodieinent of the molding apparatus of this inven= ion;

Fig. 8 is a horizontal sectional-elevation taken generally in a plane indicated by line 8 8 in Fig. 7. l

As is disclosed in applicants co-pending application, Serial o. 191,696,- led October 23, 1950, for Molding Apparatus, which describes in detail the general mold structure with the exception of the special iluid distributing member incorporated in the modincaticn of Figs; 1 through 6, the mold of such modiiication comprises a jacket l2y which includes outer shell 3 and inner mold liner i reinovablyntelesccped within shell 3, both of which are tubular shaped in the form of cylinders. A jacket space 6 is formed between shell 3 and liner 4 for circulation of a heating fluid, such as hotwatenetherethrough. Shell 3 has a peripheralAi'flangel 3 detachably connected to a base plate 9v by cap screws lo; the base plate being in turn ldetachably supported on beams H by clamping structures l2.

An annular flange i4 at the lower end of liner i seats in a recess in the bottom end of shell 3 so that when the liner is telescoped within the shell, ange le is clamped between plate 9 and the lower end of the shell. A suitable sealing gasket is clamped between iiange I4 and the lower end of the shell to seal against escape of the heating fluid from the lower end of the mold. At its upper end, shell 3 is secured to a plate I'! which forms part of the hopper (not shown) frame structure, and which also provides a closure at the top end of the shell covering jacket space 6 between the shell and the liner.

The upper end of liner 4 has a sliding fit in an aperture in plate I1; and a conventional O-ring seal 2| is provided between plate I1 and the upper end of the liner, to seal against escape of heating fluid from the upper end. Although, the liner of the mold is shown removably mounted to provide the advantages explained in said aforementioned co-pending application, it may be formed as a structurally integral unit with shell 3.

A hot water inlet pipe 22 is connected to shell 3 adjacent the lower end thereof, and an outlet pipe 23 for the hot water is also tangentially connected to the shell adjacent the upper end thereof. To eifect through circulation of the water, a plurality of spirally arranged vanes 24 are provided above inlet pipe 22; and similar vanes 25 are also provided below outlet pipeg23.

Fluid distributing member 2'! is provided below the mold to form a mounting for an inner core or mandrel 23 of the mold, and also a means for permitting circulation of heating fluid through such core, and at the same time permit free passage therethrough of actuating rods 29 for effecting movement of a cylindrical mold ejection piston 3i. As can be seen from Fig. 5, member 2'! is spider-shaped in cross section, and includes a pair of radially projecting anges 32 at diametrically opposite points, and another pair of radially proiecting flanges 33 also at diametrically opposite points. Flanges 33 are wider than flanges 32 to provide room for passages in a manner to be subsequently explained, for the purpose of permitting circulation of water; the narrower flanges 32 being primarily centering flanges.

The arrangement of the flanges is such that relatively wide radially open spaces or passages 33 are formed therebetween, providing ample clearance for actuating rods 29 so that the slurry drain freely through said passages. The outer or side edges of radial flanges 32 and 33 are in the form of arcs of a circle, to enable member 2'! to have a sliding llt within a cylindrical sleeve 33 fixed to the underside of base plate 9. A keeper bar or plate 3'! of substantially the same width as flanges 33 is provided to hold member 2'! within sleeve 33: the keeper plate being secured to sleeve 33 bv can screws 38, and member 2'! being secured to the keeper plate by cap screws 39. It will be noted that keeper plate 3'! does not block drainage through passages 34.

A fluid inlet passage 4! is provided in member 27, open at its upper end to the inside of mold core 23 and havingr a lateral extension 42 through one of the wide radial flanges 33 and which is open to the side edge of such ilanfre. Passage portion t?. communicates with an inlet aperture in sleeve 33 in which is connected a iluid inlet pipe L33. Core 23 is hollow, being closed at the top by plug 44: and its lower end is detachably connected to fluid distributing member 21, in communication with passage 4I, by means of screw threaded connection 46. A cylindrical mold cavity lll is thus formed between the outer surface of core 28 and the inner surface of liner 4; and fluid distributing member 2'! is at the lower end of the mold cavity.

In the radial flange 33 opposite the flange containing lateral passage 42, is formed a fluid outlet passage 48 located below passage 42 and open to the side edge of the flange; outlet passage 48 communicating with iluid outlet pipe 49 connected in sleeve 36. A pipe 5! has a detachable screw threaded connection 52 in member 2l', and

is in communication with outlet passage de in such member; the upper end of pipe 5| extending to a position adjacent the top of the mold. Thus, heating fluid introduced into the mold core 28 is circulated upwardly into the core, and can flow out through pipe 5I and outlet pipe 49 which may be connected to jacket inlet pipe 22.

Previously mentioned piston actuating rods 29, which are connected at their upper ends to the cylindrical ejection piston 3! in cylindrical mold cavity 4l, extend through the respective drainage passages 34 between the radial flanges of fluid distributing member 21, and are connected at their lower ends to a cross-head 53 of suitable piston actuating mechanism. In filling the mold with the slurry to be set, the piston actuating mechanism is moved so that piston 3! is at the lower end of the mold; and after the material has set to a rm self supporting mass, it can be readily ejected endwise from mold cavity 4l by movement of the piston upwardly.

Because of the relatively wide passages 34 etween the radial flanges of fluid distributing member 2'! which otherwise provides a closure for the mold cavity 4l, the aqueous slurry which may escape past piston 3| in the lowermost position thereof when the mold is first being filled, can readily drain through such passages; and ample clearance obtains for the rods 23. Therefore, any incrustation of such slurry which may form, will not interfere with free movement cf the piston actuating rods 29, as would otherwise be the case if such rods were slidable in passages of substantially the same diameter of these of the respective rods. As was previously pointed out, the incrustation occurs to a marked extent when the mold is operated alternately for molding of magnesia insulation and insulation made from the reaction of calcareous and silicious materials because of a chemical reaction which occurs between these two different types of material. Hence, the described fluid distributing member construction obviates a serious problem.

Although in the embodiment of the invention illustrated, spider member 2'! is provided with four radial flanges to provide for passages for four piston actuating rods, it is to be understood that the same principle of construction may be employed in molds of larger diameter, if so desired, where more than four circumferentially arranged piston actuating rods may be employed to eject the material from the mold.

The construction of Figs. 1 through 6 is particularly adapted for molds of relatively small diameter; and although such construction may be employed for larger diameter molds, a preferred embodiment for larger diameter molds is illustrated in Figs. '7 and 8. In such embodiment, the mold arrangement is substantially the same as that previously described comprising mold jacket 52 including outer cylindrical shell 33 and cylindrical liner 6 which is shown xedly secured to shell 63 by means including a ring S6 welded to both the shell and the liner. Heating fluid inlet pipe 6l provides means for introduction of the heating 'fluid into jacket 4's'pacxfb in the manner previously related; and as with respect to the previously described modification, l'spirall'y arranged 'vanesS'S are provided to effect thorough circulation of the heating water. The lower end of the mold structure i-s only show-n in Fie'. 7, to 'conserve space; it being understood that the construction above the portion shown is the same as that previously described. A

Liner 6d is provided with peripheral flange 'll at the lower end vthereof which is detachably mounted on base plate l2 by bolts '13; the under- 'side of 'the base plate being provided with 'suitable 'reeniorcing flanges lli. Base plate l2 is secured to supporting beams 'i6 by clamping structures il.

Mold core or mandrel T8 is supported directly on base plate 'l2 and form-s cylindrical mold cavity 'le between it and liner 6'4; 'the base l2 underlying the lower end of the mold cavity so as to form normally a 'closure member therefor; A centrally apertured plate 8l is Welded adjacent the lower end of core it; and the core is secured to base plate l2 by means including fluid distributi-ng member 82 'which is screwed at e3 in plate 8l with the underside of plate Bl abutting against a peripheral shoulder 84 on the fluid clistributing member. A nut 86, at the underside of base plate 12, is screwed onto fluid distributing member 82 to clamp core 18 against the base plate.

Fluid distributing member 82 has fluid inlet passage 87 open at the top thereof 'to permit introduction of heating fluid into the inside of core T6; and s'uch fluid inlet passage 8l is also open at the side of huid distributing member 82 through aperture 88 which is connected tc a source of heated duid supply in the manner previeusly described. Uutlet pipe 89 for conducting the heated fluid from the inside of core lo, eX- tends through passage 81 and through the huid distributing member on which the pipe is mounted, to thus provide for the circulation of the heating fluid through the inside of mold core 18.

Piston actuating rods 9| are connected to actuating cross-head 92 and are movable longitudinally in mold cavity I9 to eiect ejection of the molded material by means of the piston (not shown in Fig. 7) in the manner previously described. These rods pass with clearance through drainage passages 93 formed in base plate 'l2 to permit drainage of the slurry for the purpose described. As can be seen more clearly from Fig. 8, a plurality of arcuatel'y shaped drainage passage 93 is provided in the base plate, and a pair of the piston actuating rods passes with clearance through each passage. In operation, when the slurry is to be set in either of the modifications of Figs. 1 through 6, or Figs. 7 and 8, the mold cavities 41 and 19, respectively, are completely filled with slurry with the ejection piston at the lower end of the moldi While the piston is maintained in this position, the mold is heated to set the slurry to a firm self-'supporting mass by circulation of heating fluid, such as hot water, through respective jacket spacesv 6 and Bti. This results in thorough heating of the outer side 'of the slurry. The inner side or thev slurry is also maintained heated during the setting thereof in the mold by introduction of heating iiuid into respective hollow mold cores 28 and 18.

After the slurry is set to a firm self supporting mass, the set product is then ejected from the upper end of the mold by movement of the respective actuating rods 29 and 9| upwardly 'to move the ejection pistou upwardly. Upon ejection of the set product, the mold is ready for the neigt cycle of operation. A

`rThe Vdes'cril'ied'; type of mold is particularly adapted for the molding of aqueous slurries of maghesia or reactable ealcareous-silicious insulation. The products of these respective slurries, enter into a chemical reaction when brought together', which rwould. normally cause relatively rapid incrustation in the passages 34- in fluid distributing, member 21, or the passages 93 in the plate 12 if the piston actuating rods were piloted in these passages. However, since such passages are wide enough to provide ample free open space for the actuating rods, they serve as drainage passages' to allow slurries to drain freely therethrough, thus obviating'` such incrustation, and consequent damage to the mold, or relatively frequent replacement of parts.

claim:

1, Molding apparatus comprising a tubular mold member, a hollow mold vcore extending into and spaced from 'saidmold member to provide a mold cavity between it 'and the member; a closure structure adjacent an end of said member and said mold core, and including a base and a uid distributing member mounted on said base; said closure structure having a plurality of drainage passages therein adjacent an end of said mold cavity; means for circulating fluid through said core comprising a uid inlet passage in said distributing member in communication with the inside of said mold core, and an outlet pipe on Said iluid distributing member extending into the inside of said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods connected to said piston and extending through said drainage passages; said drainage 'passages being materially wider throughout their length than the width of the actuating rods to provide ample open space clearances between said passages and said rods for unobstructed flow of fluid therethrough.

e2. Molding apparatus comprising a tubular mold member, a hollow mold core within said tubular mold member spaced therefrom to provide a moldca'vity between it and the member, a uuid distributing member adjacent an end of the mold cavity and on which said core is mounted, said i'luid distributing member having fluid circulating passages therein communicating with said mold core and also drainage passages; one of said circulating passages vbeing in communication with said mold core through a pipe mounted in said nuid distributing member and extending into said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and avplurality of actuating rods connected t Said piston and itelldilg through Said drainage passages, drainage passages being materially 'wider throughout their length than the Width of the actuating rods to provide ample open space clearances between said passages and said rods for unobstructed new of fluid there= through,

3. Molding apparatus Comprising a,` tubliial` mold member, a hollow mold core within said tubular mold member spaced therefrom to provide a mold cavity between it and the member, a fluid distributing member on which said cofre is mounted, said huid distributing member having fluid circulating passages therein and also radial flanges forming radially open drainage passages between said flanges; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods; connected to said piston and extending through said radially open drainage passages.

4. Molding apparatus comprising a tubular mold member, a hollow mold core within said tubular mold member spaced therefrom to provide a mold cavity between it and the member, a fluid distributing member upon which an end of said core is mounted, said fluid distributing member having radial flanges forming radially open drainage passages between said flanges; means for circulating fluid through said core comprising a fluid inlet passage in said duid distributing member open to the top thereof and to the sidi` edge of a radial flange of said member, a duid outlet passage open to the side edge of a radial flange of said member, and a pipe mounted on said member in communication with. said outlet passage and extending into the inside of said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods connected to said piston and extending through said radially open drainage passages.

5. Molding apparatus comprising a tubular mold member, a hollow mold core within said tubular mold member spaced therefrom to provide a mold cavity between it and the member, a fluid distributing member upon which an end. of said core is mounted, a sleeve about said distributing member, said fluid distributing meinber having radial flanges forming racially open drainage passages between said flanges; means for circulating fluid through said core comprising a fluid inlet passage in said fluid distributing member open to the top thereof and to the side edge of one of said radial iianges of said member and in communication with a fluid inlet aperture in said sleeve, a fluid outlet passage open to the side edge of another radial flange of said member and in communication with an outlet aperture in said sleeve, and a pipe mounted on said member in communication with said outlet passage and extending into the inside of said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods connected to said piston and extending through said radially open drainage passages.

6. Molding apparatus comprising a base; a jacket positioned on said base including an outer substantially cylindrical shell and a substantially cylindrical mold liner within said shell, said shell having an opening for introduction of fluid into the jacket; a sleeve on said base under said jacket; a fluid distributing member in said sleeve; a hollow mold core mounted on said member and extending into and spaced from said liner to provide a mold cavity between it and the liner, said fluid distributing member having radial flanges forming radially open drainage passages between said flanges; means for circulating iiuid through said core comprising a fluid inlet passage in said iiuid distributing member open to the top thereof and to the side edge of one of said radial flanges of said member and in cornmunication with a fluid inlet aperture in said sleeve, a iiuid outlet passage open to the side edge of another radial flange of said member and in communication with an outlet aperture in said sleeve, and a pipe mounted on said member in communication with said outlet passage and extending into the inside of said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods connected to said piston and extending through said radially open drainage passages.

7. Molding apparatus comprising a base; a jacket positioned on said base including an outer substantially cylindrical shell and a substantially cylindrical mold liner within said shell, said shell having an opening for introduction of iiuid into the jacket; a sleeve on said base under said jacket; a fluid distributing member in said sleeve; a hollow mold core mounted on said member and extending into and spaced from said liner to provide a mold cavity between it and the liner, said fluid distributing member having radial flanges forming radially open drainage passages between said flanges; means for circulating fluid through said core comprising a fluid inlet passage in said iluid distributing member open to the top thereof and to the side edge of one of radial flanges of said member and in communication with a fluid inlet aperture in said sleeve, a fluid outlet passage open to the side edge of another radial flange of said member and in communication with an outlet aperture in said sleeve, and a pipe mounted on said member in communication with said outlet passage and extending into the inside of said core; means securing said fluid distributing member to said sleeve without blocking drainage through said radially open passages; and means for ejecting molded material from said mold cavity comprising a piston sleeve slidably mounted in said mold cavity, and a plurality of actuating rods connectcd to said piston sleeve and extending through said radially open drainage passages.

8. Molding apparatus comprising a base, a tucular mold member positioned on said base, a hollow mold core within said tubular mold member spaced therefrom to provide a mold cavity between it and the member, a uid distributing member mounted on said base and connected to said core, means for conducting through said core comprising a iiuid inlet passage in said fluid distributing member in communication with the inside of said core and an outlet pipe on said fluid distributing member extending into the inside of said core, said base underlying an end of the mold cavity and having a plurality of drainage passages therein; and means for ejecting molded material from said mold cavity coinprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods extending through said drainage passages and connected to said piston, said drainage passages being materially wider throughce'.u their length than the width of the actuating rods to provide ample open space clearances between said passages and said rods for unobstructed flow of fluid therethrough.

9. Molding apparatus comprising a base; a jacket positioned on said base including an outer substantially cylindrical shell and a substantially cylindrical mold liner within said shell; shell having an opening for introduction of fluid into the jacket; `a fluid distributing member supported by said base; a hollow mold core adjacent said fluid distributing member and extending into and spaced from said liner to provide a mold cavity between it and the liner; said base underlying an end of the mold cavity and having a plurality of arcuate drainage passages therein; means for circulating fluid through said core comprising a fiuid inlet passage in Said fluid distributing member open to the top and to a side thereof, and an outlet pipe on said uid distributing member and extending into the inside of said core; and means for ejecting molded material from said mold cavity comprising a piston slidably mounted in said mold cavity, and a plurality of actuating rods extending with clearance through each of said drainage passages and connected to said piston.

10. Molding apparatus comprising a tubular mold member; a hollow mold core within said tubular mold member spaced therefrom to provide a mold cavity between it and the member; a iiuid distributing member on which said core is mounted; said fluid distributing member being adjacent an end of the mold cavity and having fluid drainage passages, and also a fluid inlet passage in communication with the inside of said core and a fluid outlet passage; a pipe mounted on said fluid distributing member in communication with said outlet passage and extending into said core; and means for ejecting mold material from said mold cavity comprising a piston slidably mounted in said mold cavity, 'and a plurality of actuating rods connected to said piston and extending through said drainage passages; said drainage passages being materially wider throughout their length than the Width of said actuating rods to provide ample open space clearances between said passages and said rods for unobstructed flow of fluid therethrough.

HARRY P. HOOPES.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 965,005 Pauly July 19, 1910 965,007 Pauly July 19, 1910 2,211,742 Halliwell Aug. 13, 1940 2,389,673 Lodahl Nov. 27, 1945 2,432,981 Abrahams et al. Dec. 23, 1947 2,483,498 Lewon et al. Oct. 4, 1949 

